Toxoplasmosis in different animals / Clinical Signs
Cats
- Cats play major role in epidemiology of toxoplasmosis. Cats rarely show clinical signs but immune compromised cats can show acute generalized toxoplasmosis.
- Congenital toxoplasmosis in kitten that become sick after second week of birth shows anorexia, lethargy, pneumonia, icterus, vomiting, fever, diarrhea and occasional encephalitis.
Dogs
- Marked fever with lassitude ( lack of energy)
- Anorexia, diarrhea, pneumonia.
- Clinical signs are divided into four major forms: a) Generalized b) Neuromuscular c) Respiratory and d) Gastrointestinal
- Generalized form: Intermittent fever, Tonsilitis, Dyspnoea, Diarrhoea and Vomiting
- Neuromuscular form: Lesion in brain and spinal cord with symptoms of progressive paresis and last for several weeks.
- Respiratory form: Fatal within one week
- Gastrointestinal form: Diarrhoea.
Cattle
- Dyspnoea
- Coughing, sneezing
- Nasal discharge
- Trembling
- Shaking of head
- Fever
- Fibrinous deposition in peritoneal cavity
- Enlargement of sub-maxillary and brachial lymph gland
- Hemorrhagic tracheitis
- Pneumonia with consolidation
- Blood vessel wall is calcified in chronic form
Sheep
- Abortion (main symptoms in sheep)
- Lambs may be mummified, macerated, aborted, still born or may be born weak or die within a week of their birth.
Goat
- Fever
- Anorexia
- Diarrhoea
- Respiratory distress
- Death due to enteritis
- Abortion may occur
- gondii can cause early embryonic death, mummification, abortion, still birth or birth of weak kids in goats.
Pigs
- Young pigs are affected
- Fever
- Shivering
- Weakness
- Coughing
- Relaxation of abdominal muscle and diarrhea
- Pm findings include : Pneumonia, Necrosis of liver cell, Hydrothorax, Ascites, Lymphadenitis, Enteritis.
Birds
- Anorexia, Emaciation, diarrhea, blindness
- PM findings include pericarditis, diffused myocarditis, necrotic hepatitis, ulcers in alimentary tract and active follicle develops in bursa of Fabricius in some cases.
Diagnosis
- Clinical signs of toxoplasmosis are non-specific and not sufficient for definite diagnosis.
- Antemortem diagnosis may be carried out through indirect hemagglutination assay, indirect fluorescent antibody assay, latex agglutination test and ELISA.
- CSF and aqueous humor may be analyzed for the presence of tachyzoites or anti- gondii antibodies.
- Microscopic examination of tissue may reveal presence of tachyzoites or bradyzoites ( when stained with Giemsa and is most rapid diagnosis).
- LgM Ab appear sooner after infection that lga, but do not persist for more than 3 months. Increased lgM titers (>1:256) are consistent with recent infection. lgG may appear by fourth week after infection and may remain increased for years during sub-clinical infection. To be useful, lgG filters must be measured in pair sera from acute and convalescent sage ( 3-4 week apart) and must show at least and fold increase in titre.
- Since gondii is morphologically similar to other protozoan parasites, they must be differentiated from sarcocystis spoils and Neospora caninum.
Treatment
- Sulphadiazine (120 mg/kg body weight) and Pyrimethamine (1 mg/kg body weight) are drugs of choice in therapy of toxoplasmosis.
- Clindamycin are also effective but they may cause ulcerative colitis.
Prevention and control
- Daily cleaning of cat litter boxes and proper disposal of faeces.
- Raw meat should not be fed to cats.
- Pregnant women shouldn’t clean cat litter boxes.
- Vaccination of animal against Toxoplasma, to protect ewe for breeding purposes.